As an electron makes a transition from an excited state to the ground state of a hydrogen like atom/ion
(a) kinetic energy, potential energy and total energy decrease
(b) kinetic energy decreases, potential energy increases but total energy remains same
(c ) kinetic energy and total energy decrease but potential energy increases
(d) its kinetic energy increases but potential energy and total energy decrease

Answer

D

Explanation

The expressions of kinetic energy, potential energy
and total energy are
`K_n = (me^4)/(8epsilon_0^2n^2h^2) rArr K_n prop (1)/(n^2)`
`U_n = (-me^4)/(4epsilon_0^2n^2h^2) rArr `U_n prop - (1)/(n^2)` and
`E_n = (-me^4)/(8epsilon_0^2n^2h^2) rArr E_n prop -(1)/(n^2)`
in the transition from some excited state to ground
state, the value of n decreases, therefore kinetic
energy increases, but potential and total energy decrease.